Profil Toksikologi Ekstrak Heksana Alpinia conchigera (Lengkuas Kecil) Secara In vitro

Alpinia conchigera (lengkuas kecil) merupakan sejenis tumbuhan herba yang sering digunakan sebagai rawatan alternatif dalam bidang perubatan tradisional. Kajian ini dijalankan untuk menilai kesan sitotoksik, genotoksik serta mod kematian sel yang disebabkan oleh ekstrak heksana A. conchigera ke atas sel hepar Chang. Asai MTT selama 24 jam telah dijalankan untuk mengenal pasti peratus viabiliti sel hepar Chang setelah dirawat dengan ekstrak heksana A. conchigera. Keputusan menunjukkan terdapat penurunan viabiliti sel secara signifi kan (p < 0.05) dengan nilai IC50 (8.6 μg/ml) berbanding kawalan negatif. Berdasarkan nilai IC50 ini, pewarnaan AO/PI dilakukan untuk menentukan mod kematian sel hepar Chang iaitu sama ada secara apoptosis atau nekrosis. Didapati bahawa terdapat perbezaan secara signifi kan (p < 0.05) bagi mod kematian sel hepar Chang secara apoptosis berbanding kawalan negatif. Dalam kajian ini, penentuan tahap kerosakan DNA sel hepar Chang turut dilakukan dengan menggunakan asai komet beralkali dengan nilai IC10 dan IC25 yang diperoleh daripada asai MTT (4 μg/ml dan 6 μg/ml) masing-masing. Setelah sel hepar Chang dirawat dengan ekstrak heksana A. conchigera selama 2 jam, didapati terdapat perbezaan secara signifi kan (p < 0.05) bagi peratus kerosakan DNA bagi kumpulan rawatan berbanding kawalan negatif. Kesimpulannya, ekstrak heksana A. conchigera memberi kesan sitotoksik dan genotoksik terhadap sel hepar Chang serta menyebabkan kematian sel secara apoptosis

The vasorelaxant effect of Hibiscus sabdariffa linn. Polyphenol-rich extract (HPE) on rat’s isolated aorta

Hibiscus sabdariffa Linn. or also known as roselle which is rich in polyphenols, has been demonstrated to cause lowering of blood pressure in animal and clinical settings. However its exact mechanism of action particularly from polyphenolic compounds is not clearly understood. Therefore, we aimed to determine the effects of H. sabdariffa polyphenol extract (HPE) towards vascular reactivity and its mechanism of action. The HPE was studied on isolated thoracic aortic rings from normal Sprague-Dawley rats, suspended in a 15-ml organ chambers containing Krebs-Henseleit solution. The changes in tension were recorded by isometric transducer connected to data acquisition. HPE relaxed the contraction induced by phenylephrine (PE, 1 μM) in similar pattern for both endothelium-intact and endothelium denuded aortic rings in dose-dependent manner 0.1 ~ 0.9 mg/ml. The pretreatment with atropine (1 μM), a competitive muscarinic antagonist, and propranolol (1 μM), a non-selective beta- blocker did not alter HPE vasorelaxation response. In addition, HPE did not inhibit the contraction induced by extracellular Ca2+ precontracted by PE (1 μM) or KCl (60 mM), in Ca2+ -free solution, suggesting that the relaxation effect of HPE was not via inhibition of calcium channels. In conclusion, HPE demonstrated vasorelaxation effects on rat thoracic aorta although the underlying mechanism is still unknown. The vasorelaxation effect could be via angiotensin type 1 receptor inhibition in the vascular smooth muscle cells or the activation of hyperpolarizing K+ channel

Protective effects of Zingiber zerumbet ethyl acetate extract on hydrogen peroxide-induced damage of red blood cells

Zingiber zerumbet is widely used as therapeutic agent in traditional medicine and is reported to exert antioxidant activities. This study evaluated in vitro antioxidant potential of Z. zerumbet rhizome ethyl acetate extract on hydrogen peroxide (H2O2)-induced red blood cells (RBCs) damage; by measuring percentage of haemolysis, oxidative damage and morphological changes in treated RBCs. On a preliminary dose-response analysis, it was observed that incubation of RBCs with extract at doses of 50, 25, 12.5 and 6.25 μg/mL all had no significant effect on RBCs similar to NaCl control and BHT (positive control), therefore, these concentrations were used in the subsequent study. The RBCs were pre-incubated with extract in the chosen concentrations, prior to treatment with H2O2. The results showed that only 6.25 μg/mL+H2O2 group showed significantly (p<0.05) lower percentage of haemolysis and oxidative damage; indicated by low level of malondialdehyde (MDA) and protein carbonyls (PC) compared to the H2O2 alone group. Electron microscopic examination further showed that pre-treatment with 6.25 μg/mL extract reduced the H2O2 –induced morphological changes of RBCs. Phytochemical analysis of extract using Gas Chromatography Mass Spectrometry (GCMS) identified Zerumbone as the highest constituent compound (51.57%) in this extract. In conclusion, this study indicated that 6.25 μg/mL ethyl acetate extract Z. zerumbet rhizome could efficiently protect RBCs against oxidative damage induced by H2O2 and this effects could possibly due the high constituent of Zerumbone

Mutagenicity and antimutagenic activities of lactic acid bacteria (LAB) isolated from fermented durian (tempoyak)

Mutagenic and antimutagenic activities of lactic acid bacteria (LAB) Lactobacillus plantarum isolated from the local fermented durian (tempoyak) was determined by Ames test (Salmonella/microsome mutagenicity assay). Our study also involved pre-incubation assay against Salmonella typhimurium TA 98 and TA 100 bacterial strain in the presence and absence of metabolic activator S9 system. It was found that the L. plantarum showed no mutagenic activity on both S. typhimurium strain TA 98 and TA 100 in the presence and absence of metabolic activator. Significant antimutagenic activity (p < 0.05) was observed in both cell-free supernatant and bacterial cell suspension of L. plantarum as compared to the mutagenicity induced by 2-Aminoanthracene in the presence of metabolic activator. Meanwhile, in the absence of metabolic activator, only the bacterial cells of L. plantarum showed antimutagenicity acitivity against Sodium Azide and 2-Nitrofluorene. In conclusion, L. plantarum could play a vital role as chemopreventive agent by binding to mutagens and suppressing mutagenesis. Thus, L. plantarum could be consider as a good candidate for functional food development as a supplement product to prevent development of colon cancer

Effects of pterostilbene on activities and protein expression of cytochrome P450 1A1 (CYP1A1) and glutathione s-transferase (GST) in benzo[a]pyrene-induced HT-29 colorectal cancer cell line

Drug Metabolizing Enzyme (DME) has been a target of natural chemopreventive agents to inhibit, retard and reverse the process of carcinogenesis. Pterostilbene, an analog to resveratrol has been reported to possess various pharmacological benefits including chemoprevention. In our study, benzo[a]pyrene-induced HT-29 colorectal cell line was used as the DME model. The activity of phase I enzyme CYP1A as determined by the 7-ethoxyresorufin O-deethylation (EROD) assay was found to be inhibited significantly by pterostilbene at 50 μM, 75 μM and 100 μM (p ≤ 0.01, p ≤ 0.05, p ≤ 0.01 respectively) compared to the benzo[a]pyrene treated group. Meanwhile, pterostilbene induced glutathione-S-transferase (GST) activity significantly (p ≤ 0.01) at 50 μM as compared to the untreated. In addition, However, the protein expression of CYP1A1 and GST in pterostilbene treated group was not significantly affected compared to untreated. On the other hand, pterostilbene at 25 and 75 μM were able to increase the protein expression of transcription factor Nrf2 significantly (p ≤ 0.01). Results indicated that pterostilbene could reduce metabolic activation of procarcinogens and increase the detoxification process which can be potentially developed as chemopreventive agent

Fenitrothion induced oxidative stress and morphological alterations of sperm and testes in male sprague-dawley rats

OBJECTIVE: Fenitrothion residue is found primarily in soil, water and food products and can lead to a variety of toxic effects on the immune, hepatobiliary and hematological systems. However, the effects of fenitrothion on the male reproductive system remain unclear. This study aimed to evaluate the effects of fenitrothion on the sperm and testes of male Sprague-Dawley rats. METHODS: A 20 mg/kg dose of fenitrothion was administered orally by gavages for 28 consecutive days. Blood sample was obtained by cardiac puncture and dissection of the testes and cauda epididymis was performed to obtain sperm. The effects of fenitrothion on the body and organ weight, biochemical and oxidative stress, sperm characteristics, histology and ultrastructural changes in the testes were evaluated. RESULTS: Fenitrothion significantly decreased the body weight gain and weight of the epididymis compared with the control group. Fenitrothion also decreased plasma cholinesterase activity compared with the control group. Fenitrothion altered the sperm characteristics, such as sperm concentration, sperm viability and normal sperm morphology, compared with the control group. Oxidative stress markers, such as malondialdehyde, protein carbonyl, total glutathione and glutathione S-transferase, were significantly increased and superoxide dismutase activity was significantly decreased in the fenitrothion-treated group compared with the control group. The histopathological and ultrastructural examination of the testes of the fenitrothion-treated group revealed alterations corresponding with the biochemical changes compared with the control group. CONCLUSION: A 20 mg/kg dose of fenitrothion caused deleterious effects on the sperm and testes of Sprague-Dawley rats

GC-MS ANALYSIS OF TERPENOIDS FROM LEAVES OF Canarium odontophyllum Miq.(DABAI)

Terpenoids are defined as secondary metabolites with carbon backbone molecular structures consisting of isoprene (2-methylbuta-1, 3-diene) units. They demonstrate important biological activities, such as antibacterial, antiviral, antimalarial, antiinflammatory, anticancer and cholesterol synthesis inhibition activities. Canarium odontophyllum Miq. or locally known as “dabai” is an endemic plant in Sarawak, Malaysia. Its leaf compositions were examined by using the GC-MS analysis in order to compare and contrast their volatile terpenoids constituents. The terpenoids content were 36.67% and 14% for hexane and ethanol extracts, respectively. nHexadecanoic acid, phytol and octadecanoic acid were the major terpenoids constituents from the leaves of C. odontophyllum Miq. n-Hexadecanoic acid (20.22%), phytol (8.74%) and octadecanoic acid (7.54%) were found to be predominant in the hexane extract, while phytol(21.02%) and n-hexadecanoic acid (14.52%) were major constituents in the ethanol extract. The C.odontophyllum Miq. leaf constituents are also related to their biological activities and would offer promising therapeutic effects. Further investigation should be conducted to develop it as apotential therapeutic drug

Safety assessment of natural products in Malaysia: current practices, challenges, and new strategies

The belief that natural products are inherently safe is a primary reason for consumers to choose traditional medicines and herbal supplements for health maintenance and disease prevention. Unfortunately, some natural products on the market have been found to contain toxic compounds, such as heavy metals and microbes, as well as banned ingredients such as aristolochic acids. It shows that the existing regulatory system is inadequate and highlights the importance of thorough safety evaluations. In Malaysia, the National Pharmaceutical Regulatory Agency is responsible for the regulatory control of medicinal products and cosmetics, including natural products. For registration purpose, the safety of natural products is primarily determined through the review of documents, including monographs, research articles and scientific reports. One of the main factors hampering safety evaluations of natural products is the lack of toxicological data from animal studies. However, international regulatory agencies such as the European Food Safety Authority and the United States Food and Drug Administration are beginning to accept data obtained using alternative strategies such as non-animal predictive toxicological tools. Our paper discusses the use of state-of-the-art techniques, including chemometrics, in silico modelling and omics technologies and their applications to the safety assessments of natural products

Fatty acids and terpenoids from Canarium odontophyllum MIQ. Leaf and their antioxidant and cytotoxic effects on UVB-induced immortalized human keratinocytes cells (HACAT)

The study evaluated the antioxidant capacity of hexane extract of Canarium odontophyllum Miq. leaf; its fatty acids and terpenoids content; and cytotoxic effects on UVB-induced human keratinocytes (HaCaT). FRAP assay was used to determine antioxidant capacity. GC-MS analysis to identify the fatty acids and terpenoids’ in the hexane extract of Canarium odontophyllum Miq. leaf. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was carried out to measure the cytotoxic effects of the extract on UVB-induced human keratinocytes. Serial doses of up to 1000 µg/mL extract were administered before UVB irradiation of the cells. FRAP assay showed the extract was found to exhibit antioxidant activity but no significant difference in ascorbic acid equivalent antioxidant capacity (AEAC) between dose 500 µg/mL (5.00 ± 0.35 AEAC) and 1000 µg/ mL (5.70 ± 0.29 AEAC) extract. GC-MS analysis showed the extract contained 88.93% of fatty acids and terpenoids, especially n-hexadecanoic acid, spathulenol, and phytol. MTT assay showed no IC50 value for the tested extract dose on UVB-induced HaCaT. Thus, the results suggest the potential application of hexane extract of C. odontophyllum Miq. leaf in terpenoids’ studies. In-depth research and isolation of compounds of interest should be done to develop it as a viable medical phytotherapeutic agent

Potential Photochemopreventive Effect of Fatty Acids and Terpenoid Rich Leaf Extract of Canarium odontophyllum Miq. on UVB-induced Immortalized Human Keratinocytes (HaCaT) Skin Cancer Model.

Keratinocyte carcinoma is found in skin areas which are often exposed to the sun and a variety of natural products has been developed as a chemoprevention agent. One example is the Canarium odontophyllum Miq, or “Dabai”, which is an indigenous plant to Borneo, Sarawak. Fatty acids & terpenoid-rich extract from the leaf were obtained via extraction using hexane. FRAP assay showed antioxidant capacity for both 500 & 1000 µg/ml extract but not significantly different between doses. Untreated and treated immortalized human keratinocytes (HaCaT) were irradiated with UVB for 6 passages to a cumulative of 180 mJ/cm2 UVB. Findings showed 1000 ug/ml of TRCO significantly reduced p53 expression compared to the untreated group. Both 500 & 1000 µg/ml of TRCO significantly reduced the expression of Ki67 compared to the untreated group. Antioxidant and oxidative stress markers measurement revealed 500 µg/ml of TRCO significantly increased superoxide dismutase activity compared to the untreated group, both 500 & 1000 µg/ml TRCO significantly reduced catalase, glutathione peroxidase, glutathione S-transferase, and protein carbonyls compared to the untreated group. Reduced glutathione peroxidase activity is potentially due to depletion in glutathione by the UVB and extract. In vitro evaluations of TRCO on UVB-induced HaCaT skin cancer model revealed photochemopreventive properties. These promising findings validate further evaluation of C. odontophyllum Miq leaf extract as a potential therapeutic agent